Hair dryness indicator



w. M. COPELAND ETAL 3,418,963

HAIR DRYNESS INDICATOR Filed June 9, 1967 United States Patent 3,418,963 HAIR DRYNESS INDICATOR William M. Copeland, Villa Park, and Frederick J.

Ritter, Chicago, Ill., assignors to Sunbeam Corporation, Chicago, 11]., a corporation of Illinois Filed June 9, 1967, Ser. No. 645,057 Claims. (Cl. 116-67) ABSTRACT OF THE DISCLOSURE The hair dryness indicator device has the shape of a short comb for retaining the device in the users hair and contains a bi-metallic thermally responsive and concave shaped disc which will snap into a convex shape when the hair is dry with a click type sound. The indicator device being tactile since a snap action change in the position of the thermo-responsive disc will set up forces in the device to cause said device to move from a set position. Thus the user will sense or feel this movement indicating that the hair is dry.

This invention relates to an improved hair dryness indicator, and more particularly, to an audible and tactile hair dryness indicator.

It is an object of this invention to provide a very low cost and small hair dryness sensor which can be inserted into the users hair and which will give an audible and tactile signal when the hair is dry.

Briefly, in the preferred form of the invention. the device has a shape or form somewhat similar to that of a miniature Spanish comb or griptooth comb. The device comprises only three separate parts. Two parts comprise molded plastic pieces and the third part comprises a circular and concave bi-metallic thermostatic disc which will sharply snap into a convex shape with an audible click or tick noise when the hair is dry. One of the two plastic pieces is a main member having a mounting recess for the disc thermostat and integral comb teeth for inserting and retaining the sensor in the users hair. The other plastic piece is a closure member for the recess which contains the disc.

The features of the invention which are believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying single sheet of drawing.

In the drawing, FIG. 1 is a front elevation view of a r preferred form of the invention;

FIG. 2 is a rear elevation view of the device;

FIG. 3 is a side elevation view of the device; and

FIG. 4 is an enlarged sectional view taken along the section line 44 of FIG. 1.

In an actual working embodiment of the invention the device is about one-half the size illustrated in FIGS. 1-3 of the drawing. That is to say, the overall length of the device is about two inches, and its main body portion has a diameter of about one inch. The thickness of the main body portion is about inch, and the diameter of the circular thermostatic disc is about inch.

The device comprises three separate pieces. Two of the pieces, designated generally by reference numerals and 11 are constructed from molded plastic material. The third piece is a circular bi-metallic thermostatic disc 12. The plastic piece 10 has a main body portion 13 and a plurality of integrally formed comb-like teeth 14. The teeth are four in number, although fewer or less teeth could be employed. The teeth are arranged along one side of the body portion 13 and project from the periphery thereof.

Teeth 14 are for the purpose of retaining the device in the users hair.

The main body portion 13 has a recess 15 formed therein which is closed by the other molded plastic member 11 which comprises a cover or closure for recess 15. In its cold position the disc 12 has a concave shape. When it comes up to temperature, it will assume a convex shape with a snap action so as to produce an audible click-type noise. When viewing FIG. 4, the right hand side of disc 12 is the low expansion side thereof, and the left hand side is the high expansion side thereof. Accordingly, when disc 12 is heated and reaches a p re-selected temperature, it will assume a convex shape which is a shape opposite to that of what is illustrated in FIG. 4. The operation and construction of disc 12 is well known and understood by those skilled in the art and is a component which can be readily purchased on the marketplace from thermostat manufacturers. The disc 12 can be designed so as to snap into a convex shape at a preselected temperature. In the instant invention, the disc 12 snaps into a convex shape with a click or tick noise at a temperature of about degrees F.

The recess 15 is oversize with respect to the disc 12 for a purpose which will become clear hereinafter. As illustrated in FIGS. 2 and 4, a plurality of integral support lugs or ledges 16 are formed about the periphery of recess 15 in spaced relationship. In addition, the inside surface of cover 11 has an integrally formed centrally positioned lug 17 which extends from cover 11 towards the central portion of disc 12. The lug 17 is spaced from the central portion of disc 12 by a slight or minute gap 18. The diameter of recess 15 is slightly larger than the diameter of disc 12. Accordingly, disc 12 is mounted in recess 15 between the lugs 16 and 17 in a slightly loose fashion. The reason for this and the gap 18 is so as to prevent stressing or distorting the disc 12 when it is assembled in the recess 15 between the main body portion 13 and cover 11. Stressing or distorting of disc 12 is to be avoided inasmuch as disc 12 is preselected to thermally respond to a fixed or given temperature and should the disc 12 be physically distorted, then this would alter the thermally responsive characteristics of disc 12.

A circular ledge 20 is integrally formed about the periphery of recess 15 above the support lugs 16. The cover 11 fits in this ledge 20 in spaced relationship with respect to the disc 12.

The bottom of recess 15 has a plurality of vent openings 19 formed therein. These vent openings could be formed instead in the cover 11. Openings 19 are vents to the atmosphere so as to transmit the noise of the snap acting disc 12 to the atmosphere so that it can be heard to give an audible signal or indication of completion of a hair drying operation.

By viewing FIG. 3 it will be seen that the elongated teeth 14 have a slight concave curvature on the side of the device on which the vent openings 19 are formed. This is so as to facilitate inserting the teeth 14 into the hair below a hair curler form on the users head with the vented side of the device positioned closely adjacent the users scalp. The device is used in connection with the type of home hair dryer units currently on the market. Some of these home hair dryer units comprise hair drying bonnets constructed from plastic sheet material, and others have hard hair dryer hoods and are called professional type or styled hair dryers. In fact, the invention can also be used in truly professional hair dryers found in beauty parlors. These home and professional hair dryers blow warm drying air through the hair dryer caps or hoods on to the womans 'hair. In the assignees form of home hair dryer the drying air has a temperature of about degrees F. During the hair drying process the maximum temperature at the womans scalp is in the range of about 109, 110 degrees F. As long as the hair is wet or moist the temperature at the scalp will remain in this range. The warmer drying air is constantly removing moisture or vapor from the hair and scalp at this time. However, when all the hair becomes dry then the temperature at the scalp will commence to exceed the range of about 109, 110 degrees F. The thermostatic disc 12 will respond to this sudden increase in temperature. It will do this by becoming thermally distorted so as to snap from its concave to its convex shape with a click noise. This audible signal tells the woman that her hair is completely dry.

For proper utilization of the hair dryness sensor and indicator the device should be inserted in that portion of the womans hair which is thickest and most diflicult to dry and the last to become thoroughly dry. The thermostat 12 thermally lags the ambient air about the womans head inside the hair drying bonnet. Therefore, it is designed to change shape and give an audible signal at a temperature of about 120 degrees F. When the disc 12 reaches this temperature, the temperature at the womans scalp is commencing to exceed the temperature of about 109, 110 degrees F.

The vents 19 are preferably positioned on the side of the device closest to the users scalp. The vents are for the purpose of transmitting the noise of the disc to the atmosphere, and also, to make the disc more quickly responsive to the temperature adjacent the user scalp without appreciable thermal or time lag. Since the indicator device is also tactile the user will know when the hair is dry since the user Will sense or feel the movement of said device caused by said change in condition of the disc from a concave to a convex shape. This addi tional signal besides the audible click noise is desirable since some hair dryers are noisy. However, the user will still be told when hair drying is done even though the user does not hear the disc noise since the indicator is tactile and audible.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and therefore, it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A hair dryness tactile and audible indicator device comprising a member having a main portion formed with a plurality of integral comb-like teeth, a recess formed in said main portion, a temperature responsive bi-metallic element having a concave shape positioned in said recess, and a closure for said recess, means communicating between said recess and the exterior of said main portion, said teeth being adapted to retain said device inserted in users hair, said bi-metallic element being adapted to snap into a convex shape and emit an audible sound through said means when said hair is dry, and positioning of said device in a users hair enabling said user to feel the change in condition of said bi-metallic element from a concave to convex shape by tactile sense.

2. In a device is in claim 1, wherein said member and closure are constructed from molded plastic material, said bi-metallic element having a circular disc shape, said main portion, recess and closure having a circular shape, said main portion having a shallow thickness relative to its diameter whereby it has a fiat circular shape, said teeth protruding from the peripheral edge of said main portion along one side thereof, a plurality of small openings formed in said device on one side of said disc to vent said recess to the atmosphere, and said main portion, disc and closure being superposed with respect to each other when assembled together.

3. In a device as in claim 2, wherein said main portion has a diameter of about one inch, the total length of said main portion and its protruding teeth is about two inches, the thickness of said main portion including its assembled closure is about A inch, the diameter of said bi-metallic element being about /3 inch, and said bi-metallic element being adapted tosharply snap into a convex shape with an audible sound at at temperature of about degrees F.

4. In a device as in claim 2, wherein a plurality of spaced ledges are formed along the periphery of said recess to retain said bi-metallic element spaced from the bottom of said recess, and the inside surface of said closure having a centrally positioned and integral lug formed thereon extending therefrom toward the central portion of said bi-metallic element, the inner end of said lug and said bi-metallic element central portion being spaced from each other, and the diameter of said recess being larger than the diameter of said bi-metallic element whereby said ledges and lug loosely retain said disc positioned in said recess.

5. In a device as in claim 4, said teeth having a slight concave curvature along the side of said device on which said vent openings are positioned, whereby when said device is inserted into a users hair the side thereof containing said vent openings faces and is positioned closely adjacent the users scalp.

References Cited UNITED STATES PATENTS 1,469,450 10/1923 Stone 132-148 2,136,055 11/1938 Miller 73-359 2,939,320 6/1960 Frey et al. 73-378.3 3,130,585 4/1964 Koci 73-3783 LOUIS J. CAPOZI, Primary Examiner.

US. Cl. X.R. 

